<?php

if (!defined('BASEPATH'))
  exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package		CodeIgniter
 * @author		ExpressionEngine Dev Team
 * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license		http://codeigniter.com/user_guide/license.html
 * @link		http://codeigniter.com
 * @since		Version 1.0
 * @filesource
 */
// ------------------------------------------------------------------------

/**
 * Active Record Class
 *
 * This is the platform-independent base Active Record implementation class.
 *
 * @package		CodeIgniter
 * @subpackage	Drivers
 * @category	Database
 * @author		ExpressionEngine Dev Team
 * @link		http://codeigniter.com/user_guide/database/
 */
class CI_DB_active_record extends CI_DB_driver {

  var $ar_select = array();
  var $ar_distinct = FALSE;
  var $ar_from = array();
  var $ar_join = array();
  var $ar_where = array();
  var $ar_like = array();
  var $ar_groupby = array();
  var $ar_having = array();
  var $ar_keys = array();
  var $ar_limit = FALSE;
  var $ar_offset = FALSE;
  var $ar_order = FALSE;
  var $ar_orderby = array();
  var $ar_set = array();
  var $ar_wherein = array();
  var $ar_aliased_tables = array();
  var $ar_store_array = array();
  // Active Record Caching variables
  var $ar_caching = FALSE;
  var $ar_cache_exists = array();
  var $ar_cache_select = array();
  var $ar_cache_from = array();
  var $ar_cache_join = array();
  var $ar_cache_where = array();
  var $ar_cache_like = array();
  var $ar_cache_groupby = array();
  var $ar_cache_having = array();
  var $ar_cache_orderby = array();
  var $ar_cache_set = array();
  var $ar_no_escape = array();
  var $ar_cache_no_escape = array();

  // --------------------------------------------------------------------

  /**
   * Select
   *
   * Generates the SELECT portion of the query
   *
   * @param	string
   * @return	object
   */
  public function select($select = '*', $escape = NULL) {
    if (is_string($select)) {
      $select = explode(',', $select);
    }

    foreach ($select as $val) {
      $val = trim($val);

      if ($val != '') {
        $this->ar_select[] = $val;
        $this->ar_no_escape[] = $escape;

        if ($this->ar_caching === TRUE) {
          $this->ar_cache_select[] = $val;
          $this->ar_cache_exists[] = 'select';
          $this->ar_cache_no_escape[] = $escape;
        }
      }
    }
    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Select Max
   *
   * Generates a SELECT MAX(field) portion of a query
   *
   * @param	string	the field
   * @param	string	an alias
   * @return	object
   */
  public function select_max($select = '', $alias = '') {
    return $this->_max_min_avg_sum($select, $alias, 'MAX');
  }

  // --------------------------------------------------------------------

  /**
   * Select Min
   *
   * Generates a SELECT MIN(field) portion of a query
   *
   * @param	string	the field
   * @param	string	an alias
   * @return	object
   */
  public function select_min($select = '', $alias = '') {
    return $this->_max_min_avg_sum($select, $alias, 'MIN');
  }

  // --------------------------------------------------------------------

  /**
   * Select Average
   *
   * Generates a SELECT AVG(field) portion of a query
   *
   * @param	string	the field
   * @param	string	an alias
   * @return	object
   */
  public function select_avg($select = '', $alias = '') {
    return $this->_max_min_avg_sum($select, $alias, 'AVG');
  }

  // --------------------------------------------------------------------

  /**
   * Select Sum
   *
   * Generates a SELECT SUM(field) portion of a query
   *
   * @param	string	the field
   * @param	string	an alias
   * @return	object
   */
  public function select_sum($select = '', $alias = '') {
    return $this->_max_min_avg_sum($select, $alias, 'SUM');
  }

  // --------------------------------------------------------------------

  /**
   * Processing Function for the four functions above:
   *
   * 	select_max()
   * 	select_min()
   * 	select_avg()
   *  select_sum()
   *
   * @param	string	the field
   * @param	string	an alias
   * @return	object
   */
  protected function _max_min_avg_sum($select = '', $alias = '', $type = 'MAX') {
    if (!is_string($select) OR $select == '') {
      $this->display_error('db_invalid_query');
    }

    $type = strtoupper($type);

    if (!in_array($type, array('MAX', 'MIN', 'AVG', 'SUM'))) {
      show_error('Invalid function type: ' . $type);
    }

    if ($alias == '') {
      $alias = $this->_create_alias_from_table(trim($select));
    }

    $sql = $type . '(' . $this->_protect_identifiers(trim($select)) . ') AS ' . $alias;

    $this->ar_select[] = $sql;

    if ($this->ar_caching === TRUE) {
      $this->ar_cache_select[] = $sql;
      $this->ar_cache_exists[] = 'select';
    }

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Determines the alias name based on the table
   *
   * @param	string
   * @return	string
   */
  protected function _create_alias_from_table($item) {
    if (strpos($item, '.') !== FALSE) {
      return end(explode('.', $item));
    }

    return $item;
  }

  // --------------------------------------------------------------------

  /**
   * DISTINCT
   *
   * Sets a flag which tells the query string compiler to add DISTINCT
   *
   * @param	bool
   * @return	object
   */
  public function distinct($val = TRUE) {
    $this->ar_distinct = (is_bool($val)) ? $val : TRUE;
    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * From
   *
   * Generates the FROM portion of the query
   *
   * @param	mixed	can be a string or array
   * @return	object
   */
  public function from($from) {
    foreach ((array) $from as $val) {
      if (strpos($val, ',') !== FALSE) {
        foreach (explode(',', $val) as $v) {
          $v = trim($v);
          $this->_track_aliases($v);

          $this->ar_from[] = $this->_protect_identifiers($v, TRUE, NULL, FALSE);

          if ($this->ar_caching === TRUE) {
            $this->ar_cache_from[] = $this->_protect_identifiers($v, TRUE, NULL, FALSE);
            $this->ar_cache_exists[] = 'from';
          }
        }
      } else {
        $val = trim($val);

        // Extract any aliases that might exist.  We use this information
        // in the _protect_identifiers to know whether to add a table prefix
        $this->_track_aliases($val);

        $this->ar_from[] = $this->_protect_identifiers($val, TRUE, NULL, FALSE);

        if ($this->ar_caching === TRUE) {
          $this->ar_cache_from[] = $this->_protect_identifiers($val, TRUE, NULL, FALSE);
          $this->ar_cache_exists[] = 'from';
        }
      }
    }

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Join
   *
   * Generates the JOIN portion of the query
   *
   * @param	string
   * @param	string	the join condition
   * @param	string	the type of join
   * @return	object
   */
  public function join($table, $cond, $type = '') {
    if ($type != '') {
      $type = strtoupper(trim($type));

      if (!in_array($type, array('LEFT', 'RIGHT', 'OUTER', 'INNER', 'LEFT OUTER', 'RIGHT OUTER'))) {
        $type = '';
      } else {
        $type .= ' ';
      }
    }

    // Extract any aliases that might exist.  We use this information
    // in the _protect_identifiers to know whether to add a table prefix
    $this->_track_aliases($table);

    // Strip apart the condition and protect the identifiers
    if (preg_match('/([\w\.]+)([\W\s]+)(.+)/', $cond, $match)) {
      $match[1] = $this->_protect_identifiers($match[1]);
      $match[3] = $this->_protect_identifiers($match[3]);

      $cond = $match[1] . $match[2] . $match[3];
    }

    // Assemble the JOIN statement
    $join = $type . 'JOIN ' . $this->_protect_identifiers($table, TRUE, NULL, FALSE) . ' ON ' . $cond;

    $this->ar_join[] = $join;
    if ($this->ar_caching === TRUE) {
      $this->ar_cache_join[] = $join;
      $this->ar_cache_exists[] = 'join';
    }

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Where
   *
   * Generates the WHERE portion of the query. Separates
   * multiple calls with AND
   *
   * @param	mixed
   * @param	mixed
   * @return	object
   */
  public function where($key, $value = NULL, $escape = TRUE) {
    return $this->_where($key, $value, 'AND ', $escape);
  }

  // --------------------------------------------------------------------

  /**
   * OR Where
   *
   * Generates the WHERE portion of the query. Separates
   * multiple calls with OR
   *
   * @param	mixed
   * @param	mixed
   * @return	object
   */
  public function or_where($key, $value = NULL, $escape = TRUE) {
    return $this->_where($key, $value, 'OR ', $escape);
  }

  // --------------------------------------------------------------------

  /**
   * Where
   *
   * Called by where() or or_where()
   *
   * @param	mixed
   * @param	mixed
   * @param	string
   * @return	object
   */
  protected function _where($key, $value = NULL, $type = 'AND ', $escape = NULL) {
    if (!is_array($key)) {
      $key = array($key => $value);
    }

    // If the escape value was not set will will base it on the global setting
    if (!is_bool($escape)) {
      $escape = $this->_protect_identifiers;
    }

    foreach ($key as $k => $v) {
      $prefix = (count($this->ar_where) == 0 AND count($this->ar_cache_where) == 0) ? '' : $type;

      if (is_null($v) && !$this->_has_operator($k)) {
        // value appears not to have been set, assign the test to IS NULL
        $k .= ' IS NULL';
      }

      if (!is_null($v)) {
        if ($escape === TRUE) {
          $k = $this->_protect_identifiers($k, FALSE, $escape);

          $v = ' ' . $this->escape($v);
        }

        if (!$this->_has_operator($k)) {
          $k .= ' = ';
        }
      } else {
        $k = $this->_protect_identifiers($k, FALSE, $escape);
      }

      $this->ar_where[] = $prefix . $k . $v;

      if ($this->ar_caching === TRUE) {
        $this->ar_cache_where[] = $prefix . $k . $v;
        $this->ar_cache_exists[] = 'where';
      }
    }

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Where_in
   *
   * Generates a WHERE field IN ('item', 'item') SQL query joined with
   * AND if appropriate
   *
   * @param	string	The field to search
   * @param	array	The values searched on
   * @return	object
   */
  public function where_in($key = NULL, $values = NULL) {
    return $this->_where_in($key, $values);
  }

  // --------------------------------------------------------------------

  /**
   * Where_in_or
   *
   * Generates a WHERE field IN ('item', 'item') SQL query joined with
   * OR if appropriate
   *
   * @param	string	The field to search
   * @param	array	The values searched on
   * @return	object
   */
  public function or_where_in($key = NULL, $values = NULL) {
    return $this->_where_in($key, $values, FALSE, 'OR ');
  }

  // --------------------------------------------------------------------

  /**
   * Where_not_in
   *
   * Generates a WHERE field NOT IN ('item', 'item') SQL query joined
   * with AND if appropriate
   *
   * @param	string	The field to search
   * @param	array	The values searched on
   * @return	object
   */
  public function where_not_in($key = NULL, $values = NULL) {
    return $this->_where_in($key, $values, TRUE);
  }

  // --------------------------------------------------------------------

  /**
   * Where_not_in_or
   *
   * Generates a WHERE field NOT IN ('item', 'item') SQL query joined
   * with OR if appropriate
   *
   * @param	string	The field to search
   * @param	array	The values searched on
   * @return	object
   */
  public function or_where_not_in($key = NULL, $values = NULL) {
    return $this->_where_in($key, $values, TRUE, 'OR ');
  }

  // --------------------------------------------------------------------

  /**
   * Where_in
   *
   * Called by where_in, where_in_or, where_not_in, where_not_in_or
   *
   * @param	string	The field to search
   * @param	array	The values searched on
   * @param	boolean	If the statement would be IN or NOT IN
   * @param	string
   * @return	object
   */
  protected function _where_in($key = NULL, $values = NULL, $not = FALSE, $type = 'AND ') {
    if ($key === NULL OR $values === NULL) {
      return;
    }

    if (!is_array($values)) {
      $values = array($values);
    }

    $not = ($not) ? ' NOT' : '';

    foreach ($values as $value) {
      $this->ar_wherein[] = $this->escape($value);
    }

    $prefix = (count($this->ar_where) == 0) ? '' : $type;

    $where_in = $prefix . $this->_protect_identifiers($key) . $not . " IN (" . implode(", ", $this->ar_wherein) . ") ";

    $this->ar_where[] = $where_in;
    if ($this->ar_caching === TRUE) {
      $this->ar_cache_where[] = $where_in;
      $this->ar_cache_exists[] = 'where';
    }

    // reset the array for multiple calls
    $this->ar_wherein = array();
    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Like
   *
   * Generates a %LIKE% portion of the query. Separates
   * multiple calls with AND
   *
   * @param	mixed
   * @param	mixed
   * @return	object
   */
  public function like($field, $match = '', $side = 'both') {
    return $this->_like($field, $match, 'AND ', $side);
  }

  // --------------------------------------------------------------------

  /**
   * Not Like
   *
   * Generates a NOT LIKE portion of the query. Separates
   * multiple calls with AND
   *
   * @param	mixed
   * @param	mixed
   * @return	object
   */
  public function not_like($field, $match = '', $side = 'both') {
    return $this->_like($field, $match, 'AND ', $side, 'NOT');
  }

  // --------------------------------------------------------------------

  /**
   * OR Like
   *
   * Generates a %LIKE% portion of the query. Separates
   * multiple calls with OR
   *
   * @param	mixed
   * @param	mixed
   * @return	object
   */
  public function or_like($field, $match = '', $side = 'both') {
    return $this->_like($field, $match, 'OR ', $side);
  }

  // --------------------------------------------------------------------

  /**
   * OR Not Like
   *
   * Generates a NOT LIKE portion of the query. Separates
   * multiple calls with OR
   *
   * @param	mixed
   * @param	mixed
   * @return	object
   */
  public function or_not_like($field, $match = '', $side = 'both') {
    return $this->_like($field, $match, 'OR ', $side, 'NOT');
  }

  // --------------------------------------------------------------------

  /**
   * Like
   *
   * Called by like() or orlike()
   *
   * @param	mixed
   * @param	mixed
   * @param	string
   * @return	object
   */
  protected function _like($field, $match = '', $type = 'AND ', $side = 'both', $not = '') {
    if (!is_array($field)) {
      $field = array($field => $match);
    }

    foreach ($field as $k => $v) {
      $k = $this->_protect_identifiers($k);

      $prefix = (count($this->ar_like) == 0) ? '' : $type;

      $v = $this->escape_like_str($v);

      if ($side == 'none') {
        $like_statement = $prefix . " $k $not LIKE '{$v}'";
      } elseif ($side == 'before') {
        $like_statement = $prefix . " $k $not LIKE '%{$v}'";
      } elseif ($side == 'after') {
        $like_statement = $prefix . " $k $not LIKE '{$v}%'";
      } else {
        $like_statement = $prefix . " $k $not LIKE '%{$v}%'";
      }

      // some platforms require an escape sequence definition for LIKE wildcards
      if ($this->_like_escape_str != '') {
        $like_statement = $like_statement . sprintf($this->_like_escape_str, $this->_like_escape_chr);
      }

      $this->ar_like[] = $like_statement;
      if ($this->ar_caching === TRUE) {
        $this->ar_cache_like[] = $like_statement;
        $this->ar_cache_exists[] = 'like';
      }
    }
    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * GROUP BY
   *
   * @param	string
   * @return	object
   */
  public function group_by($by) {
    if (is_string($by)) {
      $by = explode(',', $by);
    }

    foreach ($by as $val) {
      $val = trim($val);

      if ($val != '') {
        $this->ar_groupby[] = $this->_protect_identifiers($val);

        if ($this->ar_caching === TRUE) {
          $this->ar_cache_groupby[] = $this->_protect_identifiers($val);
          $this->ar_cache_exists[] = 'groupby';
        }
      }
    }
    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Sets the HAVING value
   *
   * Separates multiple calls with AND
   *
   * @param	string
   * @param	string
   * @return	object
   */
  public function having($key, $value = '', $escape = TRUE) {
    return $this->_having($key, $value, 'AND ', $escape);
  }

  // --------------------------------------------------------------------

  /**
   * Sets the OR HAVING value
   *
   * Separates multiple calls with OR
   *
   * @param	string
   * @param	string
   * @return	object
   */
  public function or_having($key, $value = '', $escape = TRUE) {
    return $this->_having($key, $value, 'OR ', $escape);
  }

  // --------------------------------------------------------------------

  /**
   * Sets the HAVING values
   *
   * Called by having() or or_having()
   *
   * @param	string
   * @param	string
   * @return	object
   */
  protected function _having($key, $value = '', $type = 'AND ', $escape = TRUE) {
    if (!is_array($key)) {
      $key = array($key => $value);
    }

    foreach ($key as $k => $v) {
      $prefix = (count($this->ar_having) == 0) ? '' : $type;

      if ($escape === TRUE) {
        $k = $this->_protect_identifiers($k);
      }

      if (!$this->_has_operator($k)) {
        $k .= ' = ';
      }

      if ($v != '') {
        $v = ' ' . $this->escape($v);
      }

      $this->ar_having[] = $prefix . $k . $v;
      if ($this->ar_caching === TRUE) {
        $this->ar_cache_having[] = $prefix . $k . $v;
        $this->ar_cache_exists[] = 'having';
      }
    }

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Sets the ORDER BY value
   *
   * @param	string
   * @param	string	direction: asc or desc
   * @return	object
   */
  public function order_by($orderby, $direction = '') {
    if (strtolower($direction) == 'random') {
      $orderby = ''; // Random results want or don't need a field name
      $direction = $this->_random_keyword;
    } elseif (trim($direction) != '') {
      $direction = (in_array(strtoupper(trim($direction)), array('ASC', 'DESC'), TRUE)) ? ' ' . $direction : ' ASC';
    }


    if (strpos($orderby, ',') !== FALSE) {
      $temp = array();
      foreach (explode(',', $orderby) as $part) {
        $part = trim($part);
        if (!in_array($part, $this->ar_aliased_tables)) {
          $part = $this->_protect_identifiers(trim($part));
        }

        $temp[] = $part;
      }

      $orderby = implode(', ', $temp);
    } else if ($direction != $this->_random_keyword) {
      $orderby = $this->_protect_identifiers($orderby);
    }

    $orderby_statement = $orderby . $direction;

    $this->ar_orderby[] = $orderby_statement;
    if ($this->ar_caching === TRUE) {
      $this->ar_cache_orderby[] = $orderby_statement;
      $this->ar_cache_exists[] = 'orderby';
    }

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Sets the LIMIT value
   *
   * @param	integer	the limit value
   * @param	integer	the offset value
   * @return	object
   */
  public function limit($value, $offset = '') {
    $this->ar_limit = (int) $value;

    if ($offset != '') {
      $this->ar_offset = (int) $offset;
    }

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Sets the OFFSET value
   *
   * @param	integer	the offset value
   * @return	object
   */
  public function offset($offset) {
    $this->ar_offset = $offset;
    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * The "set" function.  Allows key/value pairs to be set for inserting or updating
   *
   * @param	mixed
   * @param	string
   * @param	boolean
   * @return	object
   */
  public function set($key, $value = '', $escape = TRUE) {
    $key = $this->_object_to_array($key);

    if (!is_array($key)) {
      $key = array($key => $value);
    }

    foreach ($key as $k => $v) {
      if ($escape === FALSE) {
        $this->ar_set[$this->_protect_identifiers($k)] = $v;
      } else {
        $this->ar_set[$this->_protect_identifiers($k, FALSE, TRUE)] = $this->escape($v);
      }
    }

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Get
   *
   * Compiles the select statement based on the other functions called
   * and runs the query
   *
   * @param	string	the table
   * @param	string	the limit clause
   * @param	string	the offset clause
   * @return	object
   */
  public function get($table = '', $limit = null, $offset = null) {
    if ($table != '') {
      $this->_track_aliases($table);
      $this->from($table);
    }

    if (!is_null($limit)) {
      $this->limit($limit, $offset);
    }

    $sql = $this->_compile_select();

    $result = $this->query($sql);
    $this->_reset_select();
    return $result;
  }

  /**
   * "Count All Results" query
   *
   * Generates a platform-specific query string that counts all records
   * returned by an Active Record query.
   *
   * @param	string
   * @return	string
   */
  public function count_all_results($table = '') {
    if ($table != '') {
      $this->_track_aliases($table);
      $this->from($table);
    }

    $sql = $this->_compile_select($this->_count_string . $this->_protect_identifiers('numrows'));

    $query = $this->query($sql);
    $this->_reset_select();

    if ($query->num_rows() == 0) {
      return 0;
    }

    $row = $query->row();
    return (int) $row->numrows;
  }

  // --------------------------------------------------------------------

  /**
   * Get_Where
   *
   * Allows the where clause, limit and offset to be added directly
   *
   * @param	string	the where clause
   * @param	string	the limit clause
   * @param	string	the offset clause
   * @return	object
   */
  public function get_where($table = '', $where = null, $limit = null, $offset = null) {
    if ($table != '') {
      $this->from($table);
    }

    if (!is_null($where)) {
      $this->where($where);
    }

    if (!is_null($limit)) {
      $this->limit($limit, $offset);
    }

    $sql = $this->_compile_select();

    $result = $this->query($sql);
    $this->_reset_select();
    return $result;
  }

  // --------------------------------------------------------------------

  /**
   * Insert_Batch
   *
   * Compiles batch insert strings and runs the queries
   *
   * @param	string	the table to retrieve the results from
   * @param	array	an associative array of insert values
   * @return	object
   */
  public function insert_batch($table = '', $set = NULL) {
    if (!is_null($set)) {
      $this->set_insert_batch($set);
    }

    if (count($this->ar_set) == 0) {
      if ($this->db_debug) {
        //No valid data array.  Folds in cases where keys and values did not match up
        return $this->display_error('db_must_use_set');
      }
      return FALSE;
    }

    if ($table == '') {
      if (!isset($this->ar_from[0])) {
        if ($this->db_debug) {
          return $this->display_error('db_must_set_table');
        }
        return FALSE;
      }

      $table = $this->ar_from[0];
    }

    // Batch this baby
    for ($i = 0, $total = count($this->ar_set); $i < $total; $i = $i + 100) {

      $sql = $this->_insert_batch($this->_protect_identifiers($table, TRUE, NULL, FALSE), $this->ar_keys, array_slice($this->ar_set, $i, 100));

      //echo $sql;

      $this->query($sql);
    }

    $this->_reset_write();


    return TRUE;
  }

  // --------------------------------------------------------------------

  /**
   * The "set_insert_batch" function.  Allows key/value pairs to be set for batch inserts
   *
   * @param	mixed
   * @param	string
   * @param	boolean
   * @return	object
   */
  public function set_insert_batch($key, $value = '', $escape = TRUE) {
    $key = $this->_object_to_array_batch($key);

    if (!is_array($key)) {
      $key = array($key => $value);
    }

    $keys = array_keys(current($key));
    sort($keys);

    foreach ($key as $row) {
      if (count(array_diff($keys, array_keys($row))) > 0 OR count(array_diff(array_keys($row), $keys)) > 0) {
        // batch function above returns an error on an empty array
        $this->ar_set[] = array();
        return;
      }

      ksort($row); // puts $row in the same order as our keys

      if ($escape === FALSE) {
        $this->ar_set[] = '(' . implode(',', $row) . ')';
      } else {
        $clean = array();

        foreach ($row as $value) {
          $clean[] = $this->escape($value);
        }

        $this->ar_set[] = '(' . implode(',', $clean) . ')';
      }
    }

    foreach ($keys as $k) {
      $this->ar_keys[] = $this->_protect_identifiers($k);
    }

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Insert
   *
   * Compiles an insert string and runs the query
   *
   * @param	string	the table to insert data into
   * @param	array	an associative array of insert values
   * @return	object
   */
  function insert($table = '', $set = NULL) {
    if (!is_null($set)) {
      $this->set($set);
    }

    if (count($this->ar_set) == 0) {
      if ($this->db_debug) {
        return $this->display_error('db_must_use_set');
      }
      return FALSE;
    }

    if ($table == '') {
      if (!isset($this->ar_from[0])) {
        if ($this->db_debug) {
          return $this->display_error('db_must_set_table');
        }
        return FALSE;
      }

      $table = $this->ar_from[0];
    }

    $sql = $this->_insert($this->_protect_identifiers($table, TRUE, NULL, FALSE), array_keys($this->ar_set), array_values($this->ar_set));

    $this->_reset_write();
    return $this->query($sql);
  }

  // --------------------------------------------------------------------

  /**
   * Replace
   *
   * Compiles an replace into string and runs the query
   *
   * @param	string	the table to replace data into
   * @param	array	an associative array of insert values
   * @return	object
   */
  public function replace($table = '', $set = NULL) {
    if (!is_null($set)) {
      $this->set($set);
    }

    if (count($this->ar_set) == 0) {
      if ($this->db_debug) {
        return $this->display_error('db_must_use_set');
      }
      return FALSE;
    }

    if ($table == '') {
      if (!isset($this->ar_from[0])) {
        if ($this->db_debug) {
          return $this->display_error('db_must_set_table');
        }
        return FALSE;
      }

      $table = $this->ar_from[0];
    }

    $sql = $this->_replace($this->_protect_identifiers($table, TRUE, NULL, FALSE), array_keys($this->ar_set), array_values($this->ar_set));

    $this->_reset_write();
    return $this->query($sql);
  }

  // --------------------------------------------------------------------

  /**
   * Update
   *
   * Compiles an update string and runs the query
   *
   * @param	string	the table to retrieve the results from
   * @param	array	an associative array of update values
   * @param	mixed	the where clause
   * @return	object
   */
  public function update($table = '', $set = NULL, $where = NULL, $limit = NULL) {
    // Combine any cached components with the current statements
    $this->_merge_cache();

    if (!is_null($set)) {
      $this->set($set);
    }

    if (count($this->ar_set) == 0) {
      if ($this->db_debug) {
        return $this->display_error('db_must_use_set');
      }
      return FALSE;
    }

    if ($table == '') {
      if (!isset($this->ar_from[0])) {
        if ($this->db_debug) {
          return $this->display_error('db_must_set_table');
        }
        return FALSE;
      }

      $table = $this->ar_from[0];
    }

    if ($where != NULL) {
      $this->where($where);
    }

    if ($limit != NULL) {
      $this->limit($limit);
    }

    $sql = $this->_update($this->_protect_identifiers($table, TRUE, NULL, FALSE), $this->ar_set, $this->ar_where, $this->ar_orderby, $this->ar_limit);

    $this->_reset_write();
    return $this->query($sql);
  }

  // --------------------------------------------------------------------

  /**
   * Update_Batch
   *
   * Compiles an update string and runs the query
   *
   * @param	string	the table to retrieve the results from
   * @param	array	an associative array of update values
   * @param	string	the where key
   * @return	object
   */
  public function update_batch($table = '', $set = NULL, $index = NULL) {
    // Combine any cached components with the current statements
    $this->_merge_cache();

    if (is_null($index)) {
      if ($this->db_debug) {
        return $this->display_error('db_must_use_index');
      }

      return FALSE;
    }

    if (!is_null($set)) {
      $this->set_update_batch($set, $index);
    }

    if (count($this->ar_set) == 0) {
      if ($this->db_debug) {
        return $this->display_error('db_must_use_set');
      }

      return FALSE;
    }

    if ($table == '') {
      if (!isset($this->ar_from[0])) {
        if ($this->db_debug) {
          return $this->display_error('db_must_set_table');
        }
        return FALSE;
      }

      $table = $this->ar_from[0];
    }

    // Batch this baby
    for ($i = 0, $total = count($this->ar_set); $i < $total; $i = $i + 100) {
      $sql = $this->_update_batch($this->_protect_identifiers($table, TRUE, NULL, FALSE), array_slice($this->ar_set, $i, 100), $this->_protect_identifiers($index), $this->ar_where);

      $this->query($sql);
    }

    $this->_reset_write();
  }

  // --------------------------------------------------------------------

  /**
   * The "set_update_batch" function.  Allows key/value pairs to be set for batch updating
   *
   * @param	array
   * @param	string
   * @param	boolean
   * @return	object
   */
  public function set_update_batch($key, $index = '', $escape = TRUE) {
    $key = $this->_object_to_array_batch($key);

    if (!is_array($key)) {
      // @todo error
    }

    foreach ($key as $k => $v) {
      $index_set = FALSE;
      $clean = array();

      foreach ($v as $k2 => $v2) {
        if ($k2 == $index) {
          $index_set = TRUE;
        } else {
          $not[] = $k . '-' . $v;
        }

        if ($escape === FALSE) {
          $clean[$this->_protect_identifiers($k2)] = $v2;
        } else {
          $clean[$this->_protect_identifiers($k2)] = $this->escape($v2);
        }
      }

      if ($index_set == FALSE) {
        return $this->display_error('db_batch_missing_index');
      }

      $this->ar_set[] = $clean;
    }

    return $this;
  }

  // --------------------------------------------------------------------

  /**
   * Empty Table
   *
   * Compiles a delete string and runs "DELETE FROM table"
   *
   * @param	string	the table to empty
   * @return	object
   */
  public function empty_table($table = '') {
    if ($table == '') {
      if (!isset($this->ar_from[0])) {
        if ($this->db_debug) {
          return $this->display_error('db_must_set_table');
        }
        return FALSE;
      }

      $table = $this->ar_from[0];
    } else {
      $table = $this->_protect_identifiers($table, TRUE, NULL, FALSE);
    }

    $sql = $this->_delete($table);

    $this->_reset_write();

    return $this->query($sql);
  }

  // --------------------------------------------------------------------

  /**
   * Truncate
   *
   * Compiles a truncate string and runs the query
   * If the database does not support the truncate() command
   * This function maps to "DELETE FROM table"
   *
   * @param	string	the table to truncate
   * @return	object
   */
  public function truncate($table = '') {
    if ($table == '') {
      if (!isset($this->ar_from[0])) {
        if ($this->db_debug) {
          return $this->display_error('db_must_set_table');
        }
        return FALSE;
      }

      $table = $this->ar_from[0];
    } else {
      $table = $this->_protect_identifiers($table, TRUE, NULL, FALSE);
    }

    $sql = $this->_truncate($table);

    $this->_reset_write();

    return $this->query($sql);
  }

  // --------------------------------------------------------------------

  /**
   * Delete
   *
   * Compiles a delete string and runs the query
   *
   * @param	mixed	the table(s) to delete from. String or array
   * @param	mixed	the where clause
   * @param	mixed	the limit clause
   * @param	boolean
   * @return	object
   */
  public function delete($table = '', $where = '', $limit = NULL, $reset_data = TRUE) {
    // Combine any cached components with the current statements
    $this->_merge_cache();

    if ($table == '') {
      if (!isset($this->ar_from[0])) {
        if ($this->db_debug) {
          return $this->display_error('db_must_set_table');
        }
        return FALSE;
      }

      $table = $this->ar_from[0];
    } elseif (is_array($table)) {
      foreach ($table as $single_table) {
        $this->delete($single_table, $where, $limit, FALSE);
      }

      $this->_reset_write();
      return;
    } else {
      $table = $this->_protect_identifiers($table, TRUE, NULL, FALSE);
    }

    if ($where != '') {
      $this->where($where);
    }

    if ($limit != NULL) {
      $this->limit($limit);
    }

    if (count($this->ar_where) == 0 && count($this->ar_wherein) == 0 && count($this->ar_like) == 0) {
      if ($this->db_debug) {
        return $this->display_error('db_del_must_use_where');
      }

      return FALSE;
    }

    $sql = $this->_delete($table, $this->ar_where, $this->ar_like, $this->ar_limit);

    if ($reset_data) {
      $this->_reset_write();
    }

    return $this->query($sql);
  }

  // --------------------------------------------------------------------

  /**
   * DB Prefix
   *
   * Prepends a database prefix if one exists in configuration
   *
   * @param	string	the table
   * @return	string
   */
  public function dbprefix($table = '') {
    if ($table == '') {
      $this->display_error('db_table_name_required');
    }

    return $this->dbprefix . $table;
  }

  // --------------------------------------------------------------------

  /**
   * Set DB Prefix
   *
   * Set's the DB Prefix to something new without needing to reconnect
   *
   * @param	string	the prefix
   * @return	string
   */
  public function set_dbprefix($prefix = '') {
    return $this->dbprefix = $prefix;
  }

  // --------------------------------------------------------------------

  /**
   * Track Aliases
   *
   * Used to track SQL statements written with aliased tables.
   *
   * @param	string	The table to inspect
   * @return	string
   */
  protected function _track_aliases($table) {
    if (is_array($table)) {
      foreach ($table as $t) {
        $this->_track_aliases($t);
      }
      return;
    }

    // Does the string contain a comma?  If so, we need to separate
    // the string into discreet statements
    if (strpos($table, ',') !== FALSE) {
      return $this->_track_aliases(explode(',', $table));
    }

    // if a table alias is used we can recognize it by a space
    if (strpos($table, " ") !== FALSE) {
      // if the alias is written with the AS keyword, remove it
      $table = preg_replace('/\s+AS\s+/i', ' ', $table);

      // Grab the alias
      $table = trim(strrchr($table, " "));

      // Store the alias, if it doesn't already exist
      if (!in_array($table, $this->ar_aliased_tables)) {
        $this->ar_aliased_tables[] = $table;
      }
    }
  }

  // --------------------------------------------------------------------

  /**
   * Compile the SELECT statement
   *
   * Generates a query string based on which functions were used.
   * Should not be called directly.  The get() function calls it.
   *
   * @return	string
   */
  protected function _compile_select($select_override = FALSE) {
    // Combine any cached components with the current statements
    $this->_merge_cache();

    // ----------------------------------------------------------------
    // Write the "select" portion of the query

    if ($select_override !== FALSE) {
      $sql = $select_override;
    } else {
      $sql = (!$this->ar_distinct) ? 'SELECT ' : 'SELECT DISTINCT ';

      if (count($this->ar_select) == 0) {
        $sql .= '*';
      } else {
        // Cycle through the "select" portion of the query and prep each column name.
        // The reason we protect identifiers here rather then in the select() function
        // is because until the user calls the from() function we don't know if there are aliases
        foreach ($this->ar_select as $key => $val) {
          $no_escape = isset($this->ar_no_escape[$key]) ? $this->ar_no_escape[$key] : NULL;
          $this->ar_select[$key] = $this->_protect_identifiers($val, FALSE, $no_escape);
        }

        $sql .= implode(', ', $this->ar_select);
      }
    }

    // ----------------------------------------------------------------
    // Write the "FROM" portion of the query

    if (count($this->ar_from) > 0) {
      $sql .= "\nFROM ";

      $sql .= $this->_from_tables($this->ar_from);
    }

    // ----------------------------------------------------------------
    // Write the "JOIN" portion of the query

    if (count($this->ar_join) > 0) {
      $sql .= "\n";

      $sql .= implode("\n", $this->ar_join);
    }

    // ----------------------------------------------------------------
    // Write the "WHERE" portion of the query

    if (count($this->ar_where) > 0 OR count($this->ar_like) > 0) {
      $sql .= "\nWHERE ";
    }

    $sql .= implode("\n", $this->ar_where);

    // ----------------------------------------------------------------
    // Write the "LIKE" portion of the query

    if (count($this->ar_like) > 0) {
      if (count($this->ar_where) > 0) {
        $sql .= "\nAND ";
      }

      $sql .= implode("\n", $this->ar_like);
    }

    // ----------------------------------------------------------------
    // Write the "GROUP BY" portion of the query

    if (count($this->ar_groupby) > 0) {
      $sql .= "\nGROUP BY ";

      $sql .= implode(', ', $this->ar_groupby);
    }

    // ----------------------------------------------------------------
    // Write the "HAVING" portion of the query

    if (count($this->ar_having) > 0) {
      $sql .= "\nHAVING ";
      $sql .= implode("\n", $this->ar_having);
    }

    // ----------------------------------------------------------------
    // Write the "ORDER BY" portion of the query

    if (count($this->ar_orderby) > 0) {
      $sql .= "\nORDER BY ";
      $sql .= implode(', ', $this->ar_orderby);

      if ($this->ar_order !== FALSE) {
        $sql .= ($this->ar_order == 'desc') ? ' DESC' : ' ASC';
      }
    }

    // ----------------------------------------------------------------
    // Write the "LIMIT" portion of the query

    if (is_numeric($this->ar_limit)) {
      $sql .= "\n";
      $sql = $this->_limit($sql, $this->ar_limit, $this->ar_offset);
    }

    return $sql;
  }

  // --------------------------------------------------------------------

  /**
   * Object to Array
   *
   * Takes an object as input and converts the class variables to array key/vals
   *
   * @param	object
   * @return	array
   */
  public function _object_to_array($object) {
    if (!is_object($object)) {
      return $object;
    }

    $array = array();
    foreach (get_object_vars($object) as $key => $val) {
      // There are some built in keys we need to ignore for this conversion
      if (!is_object($val) && !is_array($val) && $key != '_parent_name') {
        $array[$key] = $val;
      }
    }

    return $array;
  }

  // --------------------------------------------------------------------

  /**
   * Object to Array
   *
   * Takes an object as input and converts the class variables to array key/vals
   *
   * @param	object
   * @return	array
   */
  public function _object_to_array_batch($object) {
    if (!is_object($object)) {
      return $object;
    }

    $array = array();
    $out = get_object_vars($object);
    $fields = array_keys($out);

    foreach ($fields as $val) {
      // There are some built in keys we need to ignore for this conversion
      if ($val != '_parent_name') {

        $i = 0;
        foreach ($out[$val] as $data) {
          $array[$i][$val] = $data;
          $i++;
        }
      }
    }

    return $array;
  }

  // --------------------------------------------------------------------

  /**
   * Start Cache
   *
   * Starts AR caching
   *
   * @return	void
   */
  public function start_cache() {
    $this->ar_caching = TRUE;
  }

  // --------------------------------------------------------------------

  /**
   * Stop Cache
   *
   * Stops AR caching
   *
   * @return	void
   */
  public function stop_cache() {
    $this->ar_caching = FALSE;
  }

  // --------------------------------------------------------------------

  /**
   * Flush Cache
   *
   * Empties the AR cache
   *
   * @access	public
   * @return	void
   */
  public function flush_cache() {
    $this->_reset_run(array(
        'ar_cache_select' => array(),
        'ar_cache_from' => array(),
        'ar_cache_join' => array(),
        'ar_cache_where' => array(),
        'ar_cache_like' => array(),
        'ar_cache_groupby' => array(),
        'ar_cache_having' => array(),
        'ar_cache_orderby' => array(),
        'ar_cache_set' => array(),
        'ar_cache_exists' => array(),
        'ar_cache_no_escape' => array()
    ));
  }

  // --------------------------------------------------------------------

  /**
   * Merge Cache
   *
   * When called, this function merges any cached AR arrays with
   * locally called ones.
   *
   * @return	void
   */
  protected function _merge_cache() {
    if (count($this->ar_cache_exists) == 0) {
      return;
    }

    foreach ($this->ar_cache_exists as $val) {
      $ar_variable = 'ar_' . $val;
      $ar_cache_var = 'ar_cache_' . $val;

      if (count($this->$ar_cache_var) == 0) {
        continue;
      }

      $this->$ar_variable = array_unique(array_merge($this->$ar_cache_var, $this->$ar_variable));
    }

    // If we are "protecting identifiers" we need to examine the "from"
    // portion of the query to determine if there are any aliases
    if ($this->_protect_identifiers === TRUE AND count($this->ar_cache_from) > 0) {
      $this->_track_aliases($this->ar_from);
    }

    $this->ar_no_escape = $this->ar_cache_no_escape;
  }

  // --------------------------------------------------------------------

  /**
   * Resets the active record values.  Called by the get() function
   *
   * @param	array	An array of fields to reset
   * @return	void
   */
  protected function _reset_run($ar_reset_items) {
    foreach ($ar_reset_items as $item => $default_value) {
      if (!in_array($item, $this->ar_store_array)) {
        $this->$item = $default_value;
      }
    }
  }

  // --------------------------------------------------------------------

  /**
   * Resets the active record values.  Called by the get() function
   *
   * @return	void
   */
  protected function _reset_select() {
    $ar_reset_items = array(
        'ar_select' => array(),
        'ar_from' => array(),
        'ar_join' => array(),
        'ar_where' => array(),
        'ar_like' => array(),
        'ar_groupby' => array(),
        'ar_having' => array(),
        'ar_orderby' => array(),
        'ar_wherein' => array(),
        'ar_aliased_tables' => array(),
        'ar_no_escape' => array(),
        'ar_distinct' => FALSE,
        'ar_limit' => FALSE,
        'ar_offset' => FALSE,
        'ar_order' => FALSE,
    );

    $this->_reset_run($ar_reset_items);
  }

  // --------------------------------------------------------------------

  /**
   * Resets the active record "write" values.
   *
   * Called by the insert() update() insert_batch() update_batch() and delete() functions
   *
   * @return	void
   */
  protected function _reset_write() {
    $ar_reset_items = array(
        'ar_set' => array(),
        'ar_from' => array(),
        'ar_where' => array(),
        'ar_like' => array(),
        'ar_orderby' => array(),
        'ar_keys' => array(),
        'ar_limit' => FALSE,
        'ar_order' => FALSE
    );

    $this->_reset_run($ar_reset_items);
  }

}

/* End of file DB_active_rec.php */
/* Location: ./system/database/DB_active_rec.php */